Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: Backspace to fit 12" rim on mini tub foxbody

  1. #1
    Forum Member NightMare Fox's Avatar
    Join Date
    May 2015
    Location
    Capac
    Posts
    50

    Default Backspace to fit 12" rim on mini tub foxbody

    Just as the title says...im looking to find out the correct Backspace to fit a 12" rim under my car. the car has mini tub done and coilovers.....im hearing anywhere from 6" to 7.5" BS when i have done some searches on other forums...thanks guys

  2. #2
    Club Member Speedy's Avatar
    Join Date
    Nov 2005
    Location
    Sterling Hts.
    Posts
    4,317

    Default

    Depends on if and how much the rearend has been shortened
    Mike
    86 Buick GN
    1988 Mustang 347 EFI
    Ice Nine Customs
    Grafik Intentions

  3. #3
    Club Member Fryguy302's Avatar
    Join Date
    Nov 2003
    Location
    Oxford
    Posts
    15,961

    Default

    Typically, if it's a fox rear end in a fox car and it's been shortened until the 9" end is all the way against the lower control arm mount, the car will use a 15x12 with a 6.5" backspace. Some will also use a small spacer, depending on the tire being run.
    87 Grand National (grudge car)
    Misc old Ford street cars

  4. #4
    Forum Member NightMare Fox's Avatar
    Join Date
    May 2015
    Location
    Capac
    Posts
    50

    Default

    Quote Originally Posted by Speedy View Post
    Depends on if and how much the rearend has been shortened
    well it has not been shorten...is that a must?

    Quote Originally Posted by Fryguy302 View Post
    Typically, if it's a fox rear end in a fox car and it's been shortened until the 9" end is all the way against the lower control arm mount, the car will use a 15x12 with a 6.5" backspace. Some will also use a small spacer, depending on the tire being run.
    it has a 8.8 and not shortened

  5. #5
    Club Member Fryguy302's Avatar
    Join Date
    Nov 2003
    Location
    Oxford
    Posts
    15,961

    Default

    Quote Originally Posted by NightMare Fox View Post
    well it has not been shorten...is that a must?

    it has a 8.8 and not shortened

    Kinda weird to not shorten the rear end, that's really the purpose of the mini tub, and also what makes the mini tub look cool.

    If it's not shortened at all, a 12" wheel would be like an 8.5-9" backspace, which probably doesn't exist. Best to shorten the rear end.
    87 Grand National (grudge car)
    Misc old Ford street cars

  6. #6
    Forum Member NightMare Fox's Avatar
    Join Date
    May 2015
    Location
    Capac
    Posts
    50

    Default

    Quote Originally Posted by Fryguy302 View Post
    Kinda weird to not shorten the rear end, that's really the purpose of the mini tub, and also what makes the mini tub look cool.

    If it's not shortened at all, a 12" wheel would be like an 8.5-9" backspace, which probably doesn't exist. Best to shorten the rear end.
    i was told by someone that it could be done without shortened but will do it if needed.......if so where is good place to have it done?

  7. #7
    Club Member Billydroveit's Avatar
    Join Date
    Sep 2008
    Location
    Taylor
    Posts
    5,967

    Default

    Quote Originally Posted by NightMare Fox View Post
    i was told by someone that it could be done without shortened but will do it if needed.......if so where is good place to have it done?

    I've seen it done with a 7.5" backspace wheel on a 10" rim, but not a 12. Take 2.5" off the axle and use a 6.5 BS 12" wheel like Raj said. If you're going to stretch a 28x10.5 tire on there you can get away with only 2" off the rear. To run a W tire or more you need the extra 1/2" off the axle.
    90 Red Fox Notch factory short block on 175Sold
    02 GMC Sierra 2500 ECLB Passsing everything but a gas station
    98 Cavalier 2.2 rusty but trusty
    www.SKUNKRACING.net

    Quote Originally Posted by 99slverZ View Post
    I will do actual slave labor for $25/hr. Literally I will wear a loin cloth and you can whip me for that kind of money.

  8. #8
    Club Member TWISTED's Avatar
    Join Date
    Jun 2007
    Location
    The Chop Shop
    Posts
    5,261

    Default

    I tried a 7.5 backspacing on a 12" rim but it stuck out too much. Keep in mind the crazy backspaced rims have a weird barrel shape that won't allow some brakes. My wilwood's would fit. Not even close.
    01 EXCURSION
    11 RUBICON black ops
    82 MUSTANG GT
    75 Porsche 914

  9. #9
    Forum Member NightMare Fox's Avatar
    Join Date
    May 2015
    Location
    Capac
    Posts
    50

    Default

    Quote Originally Posted by Fryguy302 View Post
    Typically, if it's a fox rear end in a fox car and it's been shortened until the 9" end is all the way against the lower control arm mount, the car will use a 15x12 with a 6.5" backspace. Some will also use a small spacer, depending on the tire being run.
    Quote Originally Posted by Billydroveit View Post
    I've seen it done with a 7.5" backspace wheel on a 10" rim, but not a 12. Take 2.5" off the axle and use a 6.5 BS 12" wheel like Raj said. If you're going to stretch a 28x10.5 tire on there you can get away with only 2" off the rear. To run a W tire or more you need the extra 1/2" off the axle.
    ok so you guys are saying 2.5" total 1.25" per side shortened......with a 6.5 BS....here is my next question what spline 33? im doing a stroked LS lq4 6.0 and adding a 88mm turbo looking around the range of 1000HP thanks for any info

  10. #10
    Club Member Fryguy302's Avatar
    Join Date
    Nov 2003
    Location
    Oxford
    Posts
    15,961

    Default

    Quote Originally Posted by NightMare Fox View Post
    ok so you guys are saying 2.5" total 1.25" per side shortened......with a 6.5 BS....here is my next question what spline 33? im doing a stroked LS lq4 6.0 and adding a 88mm turbo looking around the range of 1000HP thanks for any info
    33 will be fine for that power range, but at 1500, you will probably destroy the 33s and need to go to 35s. Also for the 12" with 6.5" bs, bring the 9" end all the way to the lower control arm mount. That distance may vary depending on the rear end, but it is likely around 2-2.5".
    87 Grand National (grudge car)
    Misc old Ford street cars

Thread Information

Users Browsing this Thread

There are currently 2 users browsing this thread. (0 members and 2 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •